JP2009248595A - Preload clearance measuring method for wheel rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure the characteristic value frequencies of a wheel rolling bearing device before and after assembling, and then precisely find a variation in the preload clearance of a rolling element from a variation in the characteristic value frequencies thereof. <P>SOLUTION: A hub unit 10 of the wheel rolling bearing device has balls 22 arranged between an outer ring part 18 and an inner ring part 20, and the inner ring part 18 is fixed and assembled to the end of a hub shaft part 14 with caulking work. The preload clearance measuring method includes: previously finding the inherent characteristics of the variation in the characteristic value frequency of the configured wheel rolling bearing device with a variation in the preload clearance amount of the balls 22; measuring the characteristic value frequencies of the individual wheel rolling bearing device to be measured, before and after caulking the end of the hub shaft part 14; and also measuring the variation in the preload clearance of the rolling element before and after caulked in accordance with the previously found inherent characteristics from the variation in the characteristic value frequencies thereof before and after caulking it. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for measuring a preload clearance of a rolling bearing device for a wheel. More specifically, the present invention relates to a method for measuring a preload clearance of a rolling bearing device for a wheel in which rolling elements are arranged between an outer ring portion and an inner ring portion, and the inner ring portion is fixed and assembled by caulking of an end portion of a hub shaft portion.

2. Description of the Related Art Conventionally, a rolling bearing device for a wheel of an automobile is configured by arranging a plurality of ball rolling elements between an outer ring and an inner ring. In this case, the rolling elements are assembled in a state where a negative clearance is given to the rolling surfaces of the outer ring and the inner ring. The preload clearance amount for the rolling elements is usually set by tightening the inner ring in the axial direction.
The inner ring is tightened in the axial direction with respect to the shaft portion of the hub shaft portion, and there is a method in which the nut is screwed and tightened. A method has been adopted in which the end of the part is caulked to the inner ring.
As a method for measuring the negative preload clearance amount of the rolling bearing device assembled by caulking, for example, there is a method according to Patent Document 1 below. In this measurement method, when the outer ring assembled by caulking is rotated, the rotational torque varies according to the preload state, and therefore, the preload clearance amount is measured by the rotational torque of the outer ring after assembly.

As is well known, the management of the negative preload clearance amount in the wheel rolling bearing device is important. That is. If the preload clearance is smaller than the appropriate value, the bearing rigidity is insufficient. If the preload clearance is extremely small, the hub may vibrate and noise may occur. On the other hand, if the preload clearance is larger than the appropriate value, the power performance and fuel consumption of the automobile may be reduced due to the increase in rotational resistance. Therefore, in order to prevent such adverse effects, in the bearing manufacturing process, it is necessary to accurately check whether or not the desired and appropriate preload clearance amount is given. It is important.
JP 11-44319 A

According to the conventional measuring method as described above, the temporary preload clearance amount of the rolling bearing device assembled by caulking can be measured, but the accuracy is insufficient.
That is, in the case of the method for measuring the preload clearance by the rotational torque as described above, the factors affecting the rotational torque are not only the preload clearance, but also the sliding resistance of the sealing device attached to the rolling bearing device, or a lubricant such as grease. In addition to the rotational torque due to these factors, the rotational torque due to these factors is also taken into account, so the accurate negative clearance with respect to the raceway surface of the rolling element is measured, not the rotational torque due to pure preload alone. I didn't.

Therefore, the present inventors paid attention to the research on the measurement element of the preload clearance amount that is not affected by the product variation, and as a result of earnest research, the present inventors found that each structural form taken by the rolling bearing device for a vehicle regardless of the presence or absence of product variation. Furthermore, it has been found that there is a certain proportional relationship between the amount of change in the preload clearance of the rolling element and the amount of change in the natural frequency of the rolling bearing device.
Therefore, the problem to be solved by the present invention is to measure the eigenvalue frequency before and after the assembly of the rolling bearing device for the wheel and to obtain the change amount of the preload clearance of the rolling element with high accuracy from the change amount of the eigenvalue frequency. is there.

In order to achieve the above object, the preload clearance measuring method for a wheel rolling bearing device according to the present invention takes the following means.
First, a first aspect of the present invention is a rolling bearing device for a wheel in which a rolling element is disposed between an outer ring portion and an inner ring portion, and the inner ring portion is fixed and assembled by caulking processing of an end portion of a hub shaft portion. In this method, the characteristic characteristic of the change amount of the eigenvalue frequency with respect to the change amount of the preload clearance amount of the rolling element in the structural form taken by the rolling bearing device for the wheel is obtained in advance, and the individual wheel to be measured is measured. For the rolling bearing device for use, the eigenvalue frequency before and after the caulking process of the end portion of the hub shaft is measured, and the rolling element of the rolling element is determined based on the characteristic characteristic obtained in advance from the amount of change in the eigenvalue frequency before and after the caulking process. The amount of change in the preload clearance before and after caulking is measured.

According to the first aspect of the present invention, the amount of change in the preload clearance before and after the caulking process of the wheel rolling bearing device can be obtained as follows.
First, the characteristic characteristic of the change amount of the eigenvalue frequency with respect to the change amount of the preload clearance amount of the rolling element in the structural form taken by the rolling bearing device for the wheel is obtained in advance. , Is what we found.
Based on the eigencharacteristics obtained above, for each wheel rolling bearing device to be measured, the eigenvalue frequency before and after caulking at the end of the hub shaft is measured, and the change in eigenvalue frequency before and after caulking And the amount of change in the preload clearance of the rolling element before and after caulking can be measured from the amount of change in the eigenvalue frequency. The required amount of change does not measure the absolute value of the preload clearance before and after caulking, but indicates the level of progress of the negative preload clearance for the rolling elements by caulking.

Next, a second invention of the present invention is a negative clearance measuring method for a rolling bearing device for a wheel according to the first invention, wherein the rolling elements arranged between the outer ring portion and the inner ring portion are made of balls. The ball train is a double row angular contact ball bearing arranged in two rows.
According to the second aspect of the invention, normally, the rolling elements of the wheel rolling bearing device use balls, and the balls are arranged in two rows in the axial direction. Preload clearance measurement can be accurately performed for a rolling bearing device for a wheel comprising a double-row angular contact ball bearing.

The method for measuring the negative clearance of the rolling bearing device for a wheel according to the present invention can obtain the following effects by taking the above-described means.
First, according to the first aspect described above, the eigenvalue frequency before and after assembly of the rolling bearing device for a wheel can be measured, and the amount of change in the preload clearance amount of the rolling element can be accurately obtained from the amount of change in the eigenvalue frequency. .
Next, according to the second invention described above, the measurement according to the first invention described above is applied to a double-row angular contact ball bearing that is normally configured as a wheel rolling bearing device, and the measurement is performed with high accuracy. be able to.

An embodiment of the best mode for carrying out the measuring method according to the present invention will be described below with reference to the drawings. In this embodiment, the rolling bearing provided in the hub unit is a so-called double row angular ball bearing.
FIG. 1 shows a hub unit composed of a double row rolling bearing of one embodiment to which a measuring method according to the present invention is applied, wherein (A) shows a top view and (B) shows a sectional view.
In the hub unit 10, a rolling bearing 16 is formed on the outer periphery of the hub shaft portion 14 of the hub 12. The rolling bearing 16 is configured by interposing a ball 22 as a rolling element between an outer ring portion 18 and an inner ring portion 20. The balls 22 are arranged in two rows in the axial direction. The balls 22 in each row are held and arranged by holding cages.

The outer ring portion 18 is formed as a substantially cylindrical member into which a hub shaft portion 14 that forms an inner ring portion 20 described later can be inserted. As shown in FIG. 1B, rolling surfaces of the balls 22 arranged in two rows are formed at the upper and lower positions of the inner peripheral surface of the cylinder. A flange 24 is integrally formed at a position above the outer peripheral surface of the cylinder. The flange 24 is attached to the knuckle arm of the suspension device for the vehicle body side member, whereby the hub unit 10 is supported on the vehicle body side.
In this embodiment, the inner ring portion 20 is constituted by an outer peripheral surface of the hub shaft portion 14 itself and an inner ring member 26 formed as an independent component. Specifically, as shown in FIG. 1B, the inner ring portion 20 that forms the rolling surface of the balls 22 arranged at the lower position is directly formed by the outer peripheral surface of the hub shaft portion 14, The inner ring portion 20 that forms the rolling surface of the balls 22 arranged in the upper position is composed of an outer peripheral surface of an inner ring member 26 that is separately formed. The inner ring member 26 has a cylindrical shape that is fitted on the hub shaft portion 14, and is fitted and attached to the hub shaft portion 14.
The hub shaft portion 14a portion to which the inner ring member 26 is fitted and attached has an outer diameter that is as small as the thickness to which the inner ring member 26 is fitted. It has a shape.
A flange 30 is formed to extend in the radial direction on the other end side of the hub shaft portion 14 (downward in FIG. 1B). As is well known, a brake disk and wheels (not shown) are attached to the flange.

The assembly of the outer ring portion 18 and the inner ring portion 20 for assembling as the hub unit 10 will be described with reference to FIG. 1B. First, two rows in the upper and lower rows are provided between the hub shaft portion 14 and the outer ring portion 18 as the inner ring portion 20. In this state, the balls 22 are arranged in the state. In this state, the inner ring member 26 formed as a separate part is fitted to the small-diameter hub shaft portion 14 a at the end of the hub shaft portion 14, and the end portion of the hub shaft portion 14 a is caulked against the end surface of the inner ring member 26. Process. By this caulking, the hub shaft portion 14 is assembled in a rotatable state. The state after the caulking process is a state where the hub shaft portion 14a is shown by a solid line in FIG.
The caulking process of the end of the hub shaft part 14a in this assembly is performed as a process of applying a load in the axial direction in which the inner ring member 26 is pressed against the step 28 of the hub shaft part 14a having a small diameter. By this processing, the preload clearance with respect to the rolling surfaces of the outer ring portion 18 and the inner ring portion 20 of the ball 22 becomes a negative clearance to which a so-called preload is applied.

Next, a method for measuring the preload clearance of the rolling bearing 16 incorporated as the hub unit 10 will be described.
First, a rolling bearing serving as a reference for the structure of the rolling bearing incorporated in the hub unit 10 (hereinafter, the rolling bearing of this reference is denoted by 16M) is prepared. The inner ring member 26 is gradually pressed in the axial direction with respect to the reference rolling bearing 16M, and the eigenvalue frequency Hz is measured at each position in the axial direction where the inner ring member 26 is pressed, and the ball at each position is measured. The negative clearance amount μm of 22 is measured, and the characteristic characteristic of the proportional relationship between the change amount of the eigenvalue frequency and the change amount of the negative preload clearance is obtained from these measured values. This characteristic is qualitatively shown in the diagram of FIG.
The eigenvalue frequency and the negative clearance amount at each position where the inner ring member 26 is pressed in the axial direction of the reference rolling bearing 16M are preferably measured as follows. In FIG. 1 (B), the end of the hub shaft portion 14a is pressed by caulking, and the standard rolling bearing 16M has a screw tightening configuration with a nut. The tightening amount of the nut is a negative clearance with respect to the ball rolling surface. And an eigenvalue frequency at each tightening position.

For measuring the eigenvalue frequency, the flange 24 of the outer ring portion 18 in FIG. 1 is vibrated with a hammer ring, acceleration is picked up at a symmetrical position, and the eigenvalue frequency is measured. In this embodiment, a point K indicated by a black triangle in FIG. 1 is a hammering position, and a point P indicated by a black circle is an acceleration pick position. The K point position and the P point position are symmetrical positions separated by 180 degrees. Note that the positions of these two points are not limited to the positions in this embodiment, and may be set as appropriate as possible. For example, in this embodiment, the positions of both points are set on the flange 24 of the outer ring portion 18, but may be set on the flange 30 of the hub 12.
As a result of intensive studies based on the eigenvalue frequency and the negative preload clearance measured as described above, the present inventors have determined that the amount of change in the eigenvalue frequency and the change in the negative preload clearance is determined by the rolling bearing. It has been found that there is a fixed proportional relationship for each structural form. This is because the rolling bearing has a spring system between the outer ring, ball, and inner ring, and the spring constant changes with the change in the preload clearance, and the preload clearance is determined from the natural frequency of the outer ring or inner ring. It has been found that changes in quantity can be measured. Based on this concept, the relationship between the two is shown qualitatively as a diagram in FIG. As shown in the characteristic graph of FIG. 2, the larger the eigenvalue frequency change amount Xc, the larger the negative preload clearance change amount Yc. The slope of this diagram will be different if the structure of the rolling bearing is different.

By measuring the natural value frequency X before and after caulking in each rolling bearing 16 to be measured from the characteristic chart measured by the reference rolling bearing 16M, the preload clearance change amount Yc can be obtained with high accuracy. The method will be described sequentially.
First, the hub unit 10 provided with the rolling bearing 16 to be measured before caulking is set on a processing apparatus table for caulking. The inner ring member 26 of the rolling bearing 16 set on the processing apparatus base is preliminarily pressed in the axial direction by appropriate means to eliminate the play clearance of the rolling bearing 16 such as play on the rolling surface of the ball 22. Keep it. This state is a state before the caulking process. FIG. 1B shows this state in which the end portion of the hub shaft portion 14a is indicated by a broken line.
Next, the eigenvalue frequency is measured for the rolling bearing 16 in the state before the caulking process in the same manner as that measured for the reference rolling bearing 16M described above. That is, in FIG. 1, the flange 24 of the outer ring portion 18 is vibrated by a hammer ring at a point K indicated by a black triangle mark, and acceleration is picked up at a point P indicated by a black circle mark at a symmetrical position, and its eigenvalue frequency is measured. . The eigenvalue frequency before caulking processing thus measured is set to X1 (Hz).

After the eigenvalue frequency X1 before caulking is measured as described above, the end of the hub shaft portion 14a is caulked on the inner ring member 26 based on a predetermined pressure, and the inner ring member 26 is moved in the axial direction. The processing is terminated by increasing the negative preload clearance of the ball 22 by pressing. This state is a state after the caulking process. This state is a state where the end portion of the hub shaft portion 14a is indicated by a solid line in FIG.
In the post-machining state of this caulking, the eigenvalue frequency in the post-machining state is measured again in the same manner as in the pre-machining state. That is, in FIG. 1, the flange 24 of the outer ring portion 18 is vibrated by a hammer ring at a point K indicated by a black triangle mark, and acceleration is picked up at a point P indicated by a black circle mark at a symmetrical position, and its eigenvalue frequency is measured. . The eigenvalue frequency after caulking is measured as X2 (Hz).

Next, the eigenvalue frequency fluctuation amount Xc before and after caulking is obtained from the eigenvalue frequencies X1 and X2 measured before and after caulking. The eigenvalue frequency fluctuation amount Xc is obtained by the following equation.
Xc (Hz) = X2-X1 (1)
When the natural frequency fluctuation amount Xc before and after caulking is obtained by the above equation (1), it is determined from the specific specific diagram shown in FIG. 2 obtained by measuring the above-described reference rolling bearing as individual measurement objects. The amount of change in the negative preload clearance of the rolling bearing 16 can be obtained. For example, when the eigenvalue frequency fluctuation amount Xc of the rolling bearing 16 to be measured obtained by the above equation (1) is Xc1 shown in FIG. 2, it becomes point a on the diagram, and the negative value corresponding to point a. The amount of change in the preload clearance is Yc1 (μm). That is, it was possible to measure that the negative clearance increased by the clearance amount Yc1 (μm) from the state where the clearance before the caulking process was eliminated. Similarly, when the eigenvalue frequency fluctuation amount Xc of the rolling bearing 16 to be measured obtained by the above equation (1) is Xc2 shown in FIG. 2, it becomes a point b on the diagram and corresponds to the point a. It can be measured that the negative clearance is increased by the clearance amount of Yc2 (μm).
The measured negative gap change amount Yc is obtained by removing the gap change quantity due to the manufacturing variation of the product and measuring the negative gap with high accuracy.

The negative clearance amount measured as described above is a negative preload clearance change amount that has changed before and after the caulking process on the ball 22 as a rolling element, and is an absolute value of the rolling bearing 16 incorporated in the hub unit 10 after the caulking process. It is not a measurement of the amount of preload clearance. If absolute caulking preload clearance needs to be measured, it can be measured by additional measurement as follows.
In this case, first, the absolute preload clearance amount of the rolling bearing 16 in the pre-working state is measured in the pre-working state of the caulking work set on the above-described processing device stand. This pre-load clearance measurement before caulking is a measurement in which a load is not acting between the ball 22 and the rolling surface, so that even with existing measurement methods, the pre-load clearance can be determined with relatively high accuracy. It can be measured. For example, it can be measured by a measurement method as disclosed in Japanese Patent Laid-Open No. 2000-9562 (Patent Document 2 described above). If the preload clearance amount measured in the state before caulking is Yb, the preload clearance amount Yc measured before and after the caulking is added to the preload clearance amount Yb to obtain the absolute value after caulking. It is measured as a negative preload caulking amount Yt.
Yt (−μm) = Yb + Yc (2)
As a result, the absolute negative preload caulking amount Yt after caulking as the final product measured is more accurate than the preload caulking amount measured by the conventional measuring method. In other words, the amount of change in pre-pressure caulking before and after caulking is not affected by product variations, and the absolute pre-load clearance measured before caulking can be measured with relatively high accuracy as described above. Therefore, the amount of absolute negative preload caulking after caulking, which is measured as a total, is also accurate.

FIG. 3 is a diagram for explaining the variation in the preload clearance amount when the negative preload clearance amount is measured only by the natural frequency after the caulking. The two lines in this diagram represent the variation width due to product variation. Assuming that the eigenvalue frequency measured after caulking is X2, the negative preload clearance amount is in the range of Yt1 to Yt2 as can be seen from the diagram of FIG. The negative preload clearance amount of the rolling bearing 16 cannot be accurately grasped. On the other hand, when measured by the above-described measuring method, it can be measured as a specific point in the width from Yt1 to Yt2, and can be measured with high accuracy.
Therefore, the pass / fail judgment as the final product of each rolling bearing to be measured can be performed with high accuracy. As a result, the variation in the preload clearance of the product is reduced, and the performance variation between products can be reduced.
In addition, the acceptance / rejection judgment as the final product is judged by the absolute negative preload clearance after caulking, but depending on the case, the preload clearance change amount Yc before and after caulking or the preload clearance before the caulking You may judge by Yb. That is, if the numerical value of the change amount of the preload clearance obtained from the change amount of the eigenvalue frequency before and after the caulking is an abnormal value, it is possible to determine in advance that the product is rejected at that stage. Similarly, if the absolute value of the preload clearance before caulking is appropriately determined by an appropriate method, an unacceptable product can be determined in advance at that stage.

The measurement method according to one embodiment of the present invention has been described above, but various other embodiments can be considered for the present invention.
For example, in the above-described embodiment, the case of measuring the negative preload clearance amount of the so-called double row angular contact ball bearing structure is described, but the target rolling bearing can be applied to various other known rolling bearings. It can be done.

The hub unit of the double row rolling bearing of one Example is shown, (A) is a top view, (B) is sectional drawing. It is an eigen-characteristic diagram which shows the relationship between eigenvalue frequency variation | change_quantity and a preload clearance variation. It is a diagram which shows the dispersion | variation in the amount of preload clearances with respect to the absolute eigenvalue frequency after a process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hub unit 12 Hub 14 Hub axial part 14a Small diameter part 16 Rolling bearing 18 Outer ring part 20 Inner ring part 22 Ball (rolling element)
24 Flange 26 Inner ring member 28 Stepped 30 Flange X Eigenvalue frequency Xc Eigenvalue frequency change Y Preload clearance Yc Preload clearance change K point Hammering position P point Acceleration pick position

Claims (2)

A rolling element is disposed between an outer ring part and an inner ring part, and the inner ring part is fixed by caulking at the end of the hub shaft part and assembled, and is a preload clearance measuring method for a wheel rolling bearing device,
The characteristic characteristic of the change amount of the eigenvalue frequency with respect to the change amount of the preload clearance amount of the rolling element in the structural form taken by the wheel rolling bearing device is obtained in advance,
For each wheel rolling bearing device to be measured, the eigenvalue frequency before and after the caulking process of the end of the hub shaft is measured, and the eigenvalue obtained in advance from the amount of change in the eigenvalue frequency before and after the caulking process. A preload clearance measuring method for a rolling bearing device for a wheel, characterized in that the amount of change in the preload clearance before and after caulking of the rolling element is measured based on the above. A preload clearance measuring method for a rolling bearing device for a wheel according to claim 1,
A rolling element disposed between the outer ring portion and the inner ring portion comprises a ball, and the ball row is a double row angular contact ball bearing arranged in two rows. Clearance measurement method.

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